During on-wing time of a jet engine deterioration occurs and leads to decreasing component efficiencies. This results in increasing Exhaust Gas Temperature (EGT) and Specific Fuel Consumption (SFC). Thereby, the condition of the High Pressure Compressor (HPC) has a comparatively large influence on these parameters defining overall engine performance. This can be explained by a changing flow field in the HPC due to geometric deviations which may occur during operation. The geometries are influenced by erosion which results in thinner airfoils, changed leading- and trailing edge geometries, shortened airfoils and increasing tip clearance. The objective for future maintenance strategies is to determine the influence of the different wear mechanisms. This can be done by experiments and Computational Fluid Dynamics (CFD). Because of the high number of different mechanisms and locations of deterioration, CFD-calculations seem to be necessary to give a detailed view of the influence of deterioration. In this regard, the following paper will present a developed procedure for analyzing, manipulating and meshing HPC-blades to simulate their flow. Therefore, three different software-routines for the mentioned steps will be shown and explained. Additionally, an example blade will pass through the process and will be manipulated for max. deviation caused by deterioration. At the end, a CFD-calculation of these blades will be carried out and analyzed for its aerodynamic behavior.

抄録全体を表示

Today's progress of degltal compression technology throw open the door to the new era of cable network. With this technology, the cable system comes to one of the best solution for the delivery of high-speed interactive servlces such as Internet access, Video-On-Demand (VOD) and telephony. The subscribers' dernand for the best media for the delivery of such servlces are growing rapldly, and Cable operators have ambitious plans to upgrade their existing networks or build new ones to satisfy the demand. The key factors that operators must consider when designing their networks are Scaiability. Reliability, and of course Cost. In this paper we analyse the upgr method of the existing networks to the reliable and scaiable architecture with minimal expense and disruption of sevices, and we introduce our new CATV equipment, that realize the future high-speed data communication via cable network in the cost-effective and reliable manner.

抄録全体を表示

It is well known that plastic deformation at the tip of a notch or defect influences the brittle fracture in structural steels. Recently the C.O.D. (crack opening displacement) concept has begun to be applied for the brittle fracture initiation of low and medium strength steels. So, it is though important to investigate the influence of the condition at the tip of a notch on the brittle fracture initiation of steel. The effect of pre-loading on the fracture strength was studied, using notched specimens of low strength structural steel (SM 50).
Standard Charpy V specimens were pre-loaded up to a general yield load by 3 or 4-point loading and then broken by 3 or 4-point loading at various strain rates at liquid nitrogen temperature. The influence of pre-loading appeared in specimens which had been pre-loaded so that their notched surface might be subjected to tensile stress, and their fracture loads tended to increase with pre-loading. However, specimens which had been pre-loaded so that their notched surface might be subjected to compressive stress, was not influenced by pre-loading apparently. The above-mentioned facts seem to indicate that the residual stress as well as the plastic deformation at the root of a notch influence the fracture strength of the notched specimens.

抄録全体を表示

Low carbon steel (SM 41) was cyclically pre-loaded under a low stress amplitude in tension-compression to 1, 3, 5, 10, 15 and 30% of fatigue life. Then the effect of cyclic pre-loading on the monotonic tensile properties and Charpy impact values was investigated. The microstructures were also observed by transmission electron microscopy. The results are as follows:
(1) Grains containing bundle and/or isolated dislocation structures were observed in the specimens cyclically pre-loaded to 5 to 15% of fatigue life. Dislocation network structures were also observed in some grains pre-loaded to 30% of fatigue life. In the case of cyclic loading under a low stress amplitude, the dislocation structure was quite different among individual grains in a specimen. These results suggest that the deformation was inhomogeneous among grains in contrast with monotonic tensile pre-deformation.
(2) All of the cyclically pre-loaded specimens showed apparent upper yield points and Lüders strain during a monotonic tensile test. These phenomena are probably caused by a dynamic strain aging of isolated dislocations during cyclic pre-loading.
(3) The increase in tensile strength of the specimens, cyclically pre-loaded up to 10% of fatigue life, is caused by the work hardening due to bundle dislocation structures, and conversly, the decrease in tensile strength of the specimens cyclically pre-loaded to 15 and 30% is caused by a certain dynamic recovery during cyclic pre-loading.
(4) The maximum impact value (I_max) decreased and the temperature at the onset of ductility (T_d) increased with increasing amount of cyclic pre-loading. These results suggest that cydic pre-loading always makes the specimens brittle.
(5) The transition temperature (T_c) decreased with increasing amount of cyclic pre-loading. However, the decrease in T_c does not relate to the increase in toughness.

抄録全体を表示

This paper presents, from the practical point of view, a calculation method for the characteristics of open-water propeller based on the so-called QCM. The QCM method has been highly appraised in this field, because of its simplicity, and especially of its reasonableness in obtaining proper solution for various types of propellers. But there exists certain problem, in calculating following the QCM method, which shows unreasonable vortex distribution especially near the tip of propeller. This requires, necessarily, sufficient number of discrete loading points as many as possible, and also large storage computer in order to obtain the proper solution. Concerning this feature in applying the QCM, the modified bound vortex system is introduced in this paper, which improves the unreasonable distribution. Furthermore, the pressure distribution on the propeller surface is also obtained by using the solution obtained from the QCM method and the concept of the equivalent 2-dimensional foil section, which consequently shows good agreement with the experimental results. Other problems referring to the effects of boss and trailing vortex contraction are also studied.

抄録全体を表示

The cytological presentation of nonpapillary in situ carcinoma of the urinary bladder was studied.In all 5 cases, a diagnosis of malignancy has been made by cytological examination of voided urine at a time when the patients had in situ carcinoma. The symptoms of the cases, such as pain on urination and urinary frequency, suggested chronic cystitis. There was no specific picture to be made by cytoscopy. But cancer cells were found in all 5 cases.
The characteristic features of malignant cells in urinary sediment from the patients with carcinoma in situ were studied, and a comparison was made with the features of malignant cells from invasive carcino ma. Cytological smears of urine from the 5 patients showed little evidence of inflammation and none of necrosis, a uniform pattern of relatively small malignant cells. Most of these cells were 13-14 microns in size, round or oval in shape. Anisocytosis was rare. Nuclei were slightly enlarged and also round or oval in shape;there were always hyperchromatic nuclei with finely distributed chromatin. A few large cells and malignant cells with degenerated bizarre nuclei were found, mixed with the uniform pattern of malignant cells.These large and malignant cells were numerous in cytological smears of urine from patients with invasive carcinoma.
Biopsy specimens appearances are sometimes misle and apt to be diagnosed as chronic cystitis, since nonpapillary in situ carcinoma denudes easily. Therefore, routine cytological examination of urinary sediment is most useful in the detection of carcinoma in situ of the urinary bladder.

抄録全体を表示

Histamine contributes to various physiologic and pathologic responses in the upper respiratory tract, including changes to epithelial permeability, afferent nerve stimulation and smooth muscle contraction. However, its physiological and pharmacological effects on paranasal sinus epithelium have not been fully elucidated. In this study, we have developed a primary culture technique using human ethmoidal epithelial cells, which demonstrated that nearly half of the outgrowthal epithelial cells were ciliated. We examined the effects of histamine and its receptor antagonists on the cultured cells by two different methods: 1) measurement of the ciliary beat frequency (CBF) by a photoelectrical method at specific predetermined ciliated sites,2) employment of a novel fluorescent water-soluble probe, FM 4-64, in order to investigate the mechanisms of activity-dependent cell membrane recycling. Histamine alone increased the CBF of the cultured cells at all concentrations tested (10^-4 M,10^-5M and 10^-6 M). The response was nearly abolished in the presence of 10^-4 M pyrilamine, whereas no significant inhibition was observed when cells were pretreated with 10^-4 M cimetidine. PronouncedF M 4-64 labelingt riggeredb y histaminea dministrationw, as observedi n the plasma membrane of the cultured cells. Pretreatment with 10^-4M pyrilamine completely inhibited these time-dependent changes in FM 4-64 labeling. We concluded that histamine stimulation acts to increase the CBF and alters membrane dynamics mediated via specific H1 receptors of the sinus epithelial cells.

抄録全体を表示

Though RGR of rice varieties is influenced to some extent by their LAR at very young stage, it is almost completely governed by their NAR which, in turn, is mainly determined by the mean photosynthetic rate of individual leaves of the plants, displayed by them under the conditions of assemblage in the field, rather than their respiratory activity. And the mean photosynthetic rate of leaves is governed not by their photosynthetic capacity originally they possess, but by the "light-receiving-coefficient" of the assemblage. The coefficient seems to be governed by the number of tillers at very early stage, but, as the assemblage grows thicker, it becomes to be decidedly governed by its total leaf area. Plant height seems to be the second facter influencing the coefficient, , and the thickness of leaves may have some influence on it, too.

抄録全体を表示

This study explores the effects of a method based on data-driven learning (DDL) for elementary school children learning English. Participants were two separate classes of sixth grade elementary school students in Japan. One class was assigned as the oral-practice group and the other the DDL group with oral practice. To investigate the effects of DDL, both groups’ pretest, posttest, and delayed posttest scores were statistically compared. The results showed that the activity based on DDL significantly improved their knowledge of plural affix -(e)s usage between countable and uncountable nouns, and they successfully retained this knowledge even after more than two weeks. In addition to these gains, the participants generally gave favorable responses to the DDL-based activity, which was probably due to its game-like format with group members. These results highlight the great potential of inductive learning based on DDL principles as an effective method for elementary school English curriculum planning.

抄録全体を表示

Stress distribution and dislocation movements around a fatigue crack tip are analyzed by means of discrete dislocation dynamics (DDD). In this study, the 2-dimensional model taking into account the crack propagation is suggested in order to investigate the effect of crack growth on the dislocation behavior and the stress field near the crack tip. A lot of dislocations are distributed in the crack wake after several cycles as a result of the crack growth. The compressive stress in the vicinity of the crack tip during unloading is produced by the reaction force of the dislocations left in the crack wake and the positive dislocations which are piled up ahead in slip lines. The dislocation behavior and crack closure phenomenon near the growing fatigue crack tip can be simulated by the model suggested in the present study.

抄録全体を表示

The objective of this study is to establish a cryopreservation protocol for shoot apices of Cardamine yezoensis. Cryopreservation was carried out using a vitrification method on shoot apices excised from in vitro cultures. Plant Vitrification Solution 2 (PVS2) was demonstrated to be an optimal vitrification solution for shoot apices in terms of its higher recovery after cryopreservation compared with PVS1 and PVS3. Smaller excised apices (1mm x 1mm square in size) showed higher regrowth after cryopreservation using PVS2 compared with larger apices (3mm x 3mm). The vitrification protocol leading to the optimal regrowth was as follows: Excised shoot tips were pretreated for 24hr at 25℃ on hormone-free basal medium with 0.4mol/L sucrose, then precultured in liquid basal medium supplemented with 0.4mol/L sucrose and 2.0mol/L glycerol (a loading solution) for 30min at 25℃. Precultured specimens were soaked in PVS2 for 60min at 0℃ in cryotubes before cryostorage for 1hr. We also examined the effects of various nutrient media on regrowth of cryopreserved apices. It was demonstrated that 4-times dilution of inorganic salts of Murashige and Skoog's medium (1/4MS) or Woody Plant medium (WPM) as basal medium resulted in higher regrowth percentages (both 66.7%) than other six media. We succeeded in improving regrowth after vitrification-based cryopreservation up to 96.7% by exchanging PVS2 twice during 60min of PVS2 loading.

抄録全体を表示

Durability in the retention of the cemented crown was examined when compressive loads of 2.5 to 10.0 kg were repeatedly applied to the occlusal plane. The chamfer type of Ni-Cr alloy crown and abutment tooth model were prepared, and they were fixed with polycarboxylate and zinc phosphate cements. The retention of the crown was decreased in seven days for polycarboxylate cement and in three days for zinc phosphate cement by storing the cemented crown and model in water at 37℃ without any loading. On the other hand, the retention was increased when relatively smaller compressive loads were repeatedly applied to the occlusal plane. It might be due to the increased mechanical interlocking resulting from denser packing or wall-to-wall expansion of the enclosed cement. It was also found that the retentive force of the cement was deteriorated by fatigue under larger levels and numbers of repeated loading or by fracture under loading at the earlier stage such as one hour after fixation.

抄録全体を表示